1) Where can i get the step link? BTW I'm in Australia, which basically means shipping it from overseas is usualy cheaper they buying it localy2) I should get it re-riveted? The rivets in the mast are still in place and the holes in this bit don't look warn or broken, It's seems as if the previous owner sailed the boat like this

Ill get practicing, What size rivets should I use?Should I just use 2?Where should I put the new rivets, slightly lower and infront or behind the current ones?

Probably 3/16 x 1/2" stainless steel. Look at the bottom of your mast and locate two rivets, one on each side, where the aluminum is thickest. Years of salt water corrosion here can make the metal pretty weak. You want to be at least 1/4" from the broken holes in the base.